21947158594 has 4 divisors (see below), whose sum is σ = 32920737894. Its totient is φ = 10973579296.

The previous prime is 21947158579. The next prime is 21947158621. The reversal of 21947158594 is 49585174912.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 20934327969 + 1012830625 = 144687^2 + 31825^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5486789647 + ... + 5486789650.

Almost surely, 2^21947158594 is an apocalyptic number.

21947158594 is a deficient number, since it is larger than the sum of its proper divisors (10973579300).

21947158594 is a wasteful number, since it uses less digits than its factorization.

21947158594 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10973579299.

The product of its digits is 3628800, while the sum is 55.

The spelling of 21947158594 in words is "twenty-one billion, nine hundred forty-seven million, one hundred fifty-eight thousand, five hundred ninety-four".